OC19.02: First trimester congenital cytomegalovirus infections: prevalence and chronology of prenatal ultrasound findings

We investigated the prevalence and chronology of ultrasound signs for primary cytomegalovirus (CMV) seroconversion in the first trimester. The additional role of MRI in detecting fetal abnormalities and the correlation between CMV viral load in amniotic fluid and adverse neonatal outcomes were evaluated. A retrospective study between 2006 and 2022 examined data from 473 patients who underwent amniocentesis for first trimester CMV seroconversion. Cases with positive CMV PCR and subsequent follow-up were included. CMV viral load, ultrasound, MRI and clinical outcomes were analysed. Ultrasound findings were categorised into severe intracranial, mild intracranial, and extracranial signs. Out of 190 patients, 37% (n = 70) had normal ultrasound findings. The most common severe intracranial signs were periventricular echogenicity (37%, n = 70) and ventriculomegaly (31%, n = 59). Severe intracranial and extracranial signs were predominantly detected early in the second trimester, while intracranial cysts, lenticulostriate vasculopathy, and synechia more commonly in the third trimester. Although most abnormalities were found on the early scans, late presentation was possible (see figure 1). Fetal MRI identified additional abnormalities in 14%. Only 3% of patients with abnormal outcome were not detected on prenatal imaging. Patients with abnormal ultrasound findings had significantly higher CMV viral loads compared to those with normal findings. Ultrasound remains a vital tool in detecting intracranial and extracranial abnormalities, while MRI complements by revealing additional anomalies. Higher CMV viral load in amniotic fluid indicates a higher risk of adverse imaging and outcomes. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.